Protective containers and methods of making the same

ABSTRACT

A cover sheet of paper or the like is laminated with a liner blanket of plastic material embodying closely spaced and hermetically sealed air cells. The composite sheet or mat is doubled upon either its longitudinal or its transverse center line to form a folder-shaped body with the cellular blanket inside. Two of the three open borders are heat sealed, hinged over upon and secured to the adjacent exterior surfaces of the body, thus completing a pressure cushioning and heat insulating container. The open border of the container is preferably crushed or compressed, to thin its walls for convenience in filling and subsequent closure.

United States Patent Keren PROTECTIVE CONTAINERS AND METHODS OF MAKINGTHE SAME [75] Inventor: Eitan Keren, Bronx, N.Y.

[73] Assignee: Sealed Air Corporation, Fair Lawn,

[22] Filed: May 21, 1973 [21] Appl. No.: 362,169

Related U.S. Application Data [63] Continuation of Ser. No. 120,896,March 4, 1971,

abandoned.

[52] U.S. Cl. 229/55, 229/48 T [51] Int. Cl B65d 33/02 [58] Field ofSearch 229/55, 48 T [56] References Cited UNITED STATES PATENTS1,944,613 l/l934 Rowe 229/55 3,349,990 10/1967 Woodford 229/55 3,494,4572/1970 Titchenal 229/55 X FOREIGN PATENTS OR APPLICATIONS 1,029,8705/1966 Great Britain 229/55 Primary Examiner-William 1. Price AssistantExaminer-Stephen P. Garbe [57] ABSTRACT A cover sheet of paper or thelike is laminated with a liner blanket of plastic material embodyingclosely spaced and hermetically sealed air cells. The composite sheet ormat is doubled upon either its longitudinal or its transverse centerline to form a folder-shaped body with the cellular blanket inside. Twoof the three open borders are heat sealed, hinged over upon and securedto the adjacent exterior surfaces of the body, thus completing apressure cushioning and heat insulating container. The open border ofthe container is preferably crushed or compressed, to thin its walls forconvenience in filling and subsequent closure.

1 Claim, 15 Drawing Figures PATENIED P53251975 3,868,056

sum 1 9f 2 INVENTOR 57w A/EFEN PROTECTIVE CONTAINERS AND METHODS OFMAKING THE SAME This application is a Continuation of application Ser.No. 120,896 filed Mar. 4, 1971, now abandoned, entitled ProtectiveContainers and Methods of Making Same.

The present invention pertains to improvements in protective containersand methods of making the same. In the progress of shipment, handlingand storage of packaged goods such as books, small delicate machineparts, brittle food stuffs, and the like, the packages are frequentlysubjected to localized exterior pressures and shocks which tend toinjure the contents. Further hazards in some instances are presented byexterior temperature and/or moisture conditions. However, success inminimizing the above hazards has been handicapped by certaincharacteristics existing either alone or in combination in thecontaining means hitherto available. Typically, such drawbacks includelack of inherent cushioning effect, both mechanical and thermal; unduebulk, weight and cost; lack of moisture repellant qualities; and unduecomplication in structure as well as in applicability to the particulargoods to be packaged.

In view of the above and related considerations, an object of thepresent invention is to provide improved protective containers which arereadily adaptable to a variety of packaging requirements.

A further object is to provide a packaging container having wallsincluding built-in pneumatic cushioning means.

Another object is to provide containers in which the pneumatic meansfurnishes augmented insulating protection against exterior temperaturechanges.

A further object is to provide a container of the above nature in whichthe cushioning and insulating means includes a blanket of flexibleplastic material in corporating closely spaced and hermetically sealedair cells.

Another object is to provide protective containers of the above typeadapted to permit hermetically sealed enclosure of the material packagedtherein.

Another object is to provide protective containers which are light,inexpensive, and of a form readily adaptable to standardization.

A still further object is to provide suitable methods or procedures forconstructing the above types of containers.

Other objects and advantages of the invention will become evident duringthe course of the following description in connection with theaccompanying drawings, in which FIG. 1 is a perspective view of typicalmatching cover and liner elements prior to being fastened together;

FIG. 2 is an enlarged fragmental cross-sectional view of the same in thegeneral plane 2-2, FIG. 1;

FIG. 3 shows the outer and inner elements joined or laminated to form acomposite wall sheet;

FIG. 4 is an enlarged fragmental section in the plane 4-4, FIG. 3;

FIG. 5 illustrates a long composite sheet doubled about its longitudinalcenter line to give it the shape of an elongated folder;

FIG. 6 illustrates sealing the long edge border of the folder of FIG. 5to convert the latter to a tube;

FIG. 7 is an enlarged fragmental cross-section of the tube along theline 77 of FIG. 6;

FIG. 8 illustrates the longitudinal border lapping and the transverseend sealing of an individual container body length cut from the tube;

FIG. 9 is an enlarged fragmental section of the lapped longitudinalborder in the plane 9-9 of FIG. 8;

FIG. 10 illustrates the lapping and securing of the sealed end border,the final sectional aspect of this detail also being shown by FIG. 9;

FIG. 11 illustrates the operation of local crushing or thinning thewalls of the open or loading end of the completed container;

FIG. 12 is an enlarged sectional illustration of the thinned loading endwalls, typically in the region 12-12 of FIG. 11;

FIG. 13 illustrates an alternative manner of forming a basic unitarycontainer folder box by transverse axial bending of an individualcomposite blank;

FIG. 14 illustrates the simultaneous heat sealing of the two oppositeside borders of the alternative folder body, and

FIG. 15 depicts the lapping over and securing of the sealed side bordersto the adjacent outer surface zones of the container body.

Referring to FIG. 1, the numeral 20 denotes an elongated web of wrappingor cover material, typically pa per, but which may alternatively be ofother materials such as sheet fabric or plastic to meet particularrequirements. Numeral 21 generally denotes a cellular cushioning blanketor liner, which may be of the nature shown in US. Pat. No. 3,142,599. Atypical enlarged detail section of such a blanket appears in FIG. 2.Referring to the latter Figure, the blanket 21 includes a flat plasticsheet 22 and an embossed plastic sheet 23 secured thereto by heatsealing throughout the narrow areas between the embossments 24, thusforming a pattern of closely spaced and hermetically sealed air cells25.

In describing the construction of containers according to the presentinvention, the process or method may best be set forth in the customarymanner of describing a number of individual operations or steps.However, it will be best understood that the inference of successivetime periods refers simply to a preferred order in which variousoperations take effect on any assumed unitary component as it passesthrough the production line; for example, operations such as those ofsteps 1, 2 and 3 are adapted to simultaneous application on successiveunits in a continuously moving system. With these considerations bornein mind, a typical set of operations is as follows:

1. The cover sheet 20 and blanket 21 are laminated or secured togetherby means of any suitable flexible adhesive in the relation illustratedin FIGS. 3 and 4, producing a composite web or mat which is designatedcollectively by the numeral 26 for convenience in reference to thediagrammatic illustrations.

2. The composite mat 26 is bent or doubled along its longitudinal centerline 27, as indicated in FIG. 5, thus converting 11 to the general shapeof an elongated folder with the cellular blanket 21 forming the interiorlining thereof.

3. The longitudinal border strips 28 of the elongated folder are heatsealed together, as by pressing them between heated rolls 29 which raisethe temperature of the engaged components to or slightly above the pointof surface fusion of the plastic material embodied in the blanket 21. Bythis means, the engaged portions of the liner 21 are pressed and fusedtogether, while the cover sheet also is heat sealed to the linerelements within the border 28, illustrated in FIG. 7. It will of coursebe understood that the thicknesses of the sheet elements of thecombinations thereof involved in the sealing of the assembly arenecessarily shown magnified in order to render the relationships clearlydiscernable in the patent drawings.

1. The sealed border portion 28 is lapped over and cemented to the coversheet 20, as shown in FIG. 9, thus converting the elongated folder tothe form of a flattened tube.

5. The tube is cut into lengths or container units 30, such as thatshown in FIG. 8.

6. The bottom end borders 31 of each unit 30 are heat sealed by meanssuch as heated rolls 32, FIG. 8, the local effect being the same as thatillustrated in FIG. 7.

7. The sealed end borders are lapped over and cemented or glued to thebodies of the units 30, as shown in FIG. 10.

8. The foregoing operations having completed the formation of acontainer permanently closed on three of its four edges, the fourth oropen loading end is preferably processed as shown in FIG. 11. Thisoperation consists in subjecting the border 82 of the open end tocrushing pressure, indicated by application of cold rollers 33 andpreferably subsequent to a preheating operation. The effect is tocompress the walls of the open end to minimal thickness, as illustratedin FIG. 12. The thinness in zone 32 not only facilitates loading ofmaterial into the container, but also provides convenience in finalclosure, the latter ranging from border folding with local retention,(as in instance of shipments required by postal law to be openable forinspection) to applications wherein hermetic scaling in of the contentis advantageous, in which case the zone 32 is readily adapted to heatsealing, or in cases precluding the use of heat, to effective plasticcementing.

The alternative version of the method of making a protective container,while basically the same as that described above, differs in certainprocedural details which render it particularly applicable in caseswherein it is desirable that the bottom of the container be of seamlessnature rather than cross sealed. The manner in which this result isaccomplished is illustrated in FIGS. 13, 14, and 15. The first operationin the process, namely, formation of the elongated composite sheet ormat, remains the same as set forth. However, instead of doubling theelongated mat on its longitudinal center line, it is next cut intoindividual blanks having lengths substantially double the depth of thedesired containers. Each such blank 34, as shown in FIG. 13, is nextdoubled about its transverse center line 35, to convert it to a folderconformation 36, with the cellular blanket 2] inside as previously setforth. The two opposite side borders 37 are heat sealed by meansillustrated as heated rollers 38. Finally the sealed borders 37 arefolded over and secured as shown in FIG. 15, and the open end 39 of thecontainer may be thinned or compressed in the manner previouslyexplained in respect to FIGS. 11 and 12.

As to the open end 39, in some applications it may be desired that theextreme outer edges consist only of the cover sheet, with the edges ofthe liner blanket spaced inwardly therefrom. This result may readily beaccomplished by making the strips of cover sheet 20 and cellular linerblanket 21, FIG. 1, of width encompassing the total length of the blankused in the folder 36, FIG. 13, but with the cover web 20 ofsufficiently greater width than the liner 21 to allow for the desirededgewise overlap; in this arrangement the spaced cutting of thelaminated or composite strip determines the width rather than the lengthof the blank, so that when the blank is bent as shown in FIG. 13, theprotrusion of the cover sheet at the open edge 39 is provided asindicated at 20a, FIG. 12.

From the foregoing description, it will be seen that the inventionprovides containers affording improved protection to their contentagainst harmful exterior influences, whether these influences bemechanical, thermal, or a combination thereof; the mechanical protection being due to the inherent and persistent flexible cushioning effectof the sealed air or gas cells 25 in the blanket 21, while the augmentedthermal protection is lodged in the heat insulating quality alsoinherent in such cells, as well as in the sealed interstices betweenthem.

In the preceding explanation the outer cover sheet 20 has been mentionedas typically of paper, which material of course is desirable in a largenumber of packaging requirements. The thickness of the paper may bevaried to meet particular service needs. For instance, flat articlessuch as books may best be served by a form having relatively thickcovers functioning as shipping envelopes in which the contents arepneumatically cushioned, while in the case of bulkier or irregularlyshaped content a thinner and hence more flexible outer covering may beadvantageous in allowing the container to act as a bag which readilyaccommodates itself to the general contours of the enclosed articles,but still maintaining its protective pneumatic cushioning throughout. Inthe production of thick or thin covered containers, either of themethods previously described may be employed; in the steps involvingheat sealing of the composite folder a higher temperature of the heatapplication is provided in the case of thicker paper covers, in order tocompensate for the somewhat higher heat insulating properties of suchpapers. In uses wherein the containers are to be expanded to relativelywide bag shape, the seamless bottom bend 35, shown in FIGS. l3, l4, and15, may be of advantage in point of maximum flattening adaptability toupright or closely packed storage.

While, as previously mentioned, the cover sheet 20 has been exemplifiedas paper, other sheet materials may be employed where best suited toparticular uses. Thus, when maximum strength and durability areimportant, as in shopping bags and the like which are intended forrepeated use, the cover sheet may be of a suitable fabric. Similarly,where complete exterior water-proofing is important, an appropriateplastic cover sheet may be embodied. Finally, in the field of foodpackaging, the inherent characteristics of shock resistance and heatinsulation, either in combination or sinvgly, also present obviousadvantages.

1 In the interest of clarity and brevity, the methods of forming thecontainers have been set forth largely in terms of the operationalcombinations involved, rather than by undue detail showing andrecapitulation of various mechanical devices by which the individualoperations may be carried out, since such devices per se are well knownin various forms which may be optionally employed. Thus the heat sealingrepresented by the hot rolls 29 and 32 in FIGS. 6 and 8 may beaccomplished by other means such as wide jaw heaters. Similarly, theproportions of the containers as to depth and extent of filler openingobviously may be varied from those shown in accordance with particularrequirements. In other words, while the invention has been set forth inpreferred simple state, it is not limited to the particular formsillustrated, as various modifications may be made without departing fromthe scope of the appended claims.

What is claimed is:

l. A protective container comprising an outer covering folded uponitself to form two layers disposed in overlying relationship and aseamless edge, a sheet of cellular material adhered to the inner facingsurfaces of said outer covering, said cellular material having a firstplastic sheet including a plurality of closely spaced embossmentsextending from one side thereof and a second plastic sheet secured tothe other side of said first sheet, at least two opposing, substantiallyparallel marginal hermetically sealed edge zones and at least one openedge zone, the cellular material disposed within said marginalhermetically sealed edge zones and said open edge zone being crushed tocollapse the cells in said cellular material and said hermeticallysealed edge zones being folded and sealed to the adjoining surfaces ofthe container whereby said hermetically sealed edge zones impart arelatively high degree of stiffness to said container and therebyenhance the protective qualities thereof.

1. A protective container comprising an outer covering folded uponitself to form two layers disposed in overlying relationship and aseamless edge, a sheet of cellular material adhered to the inner facingsurfaces of said outer covering, said cellular material having a firstplastic sheet including a plurality of closely spaced embossmentsextending from one side thereof and a second plastic sheet secured tothe other side of said first sheet, at least two opposing, substantiallyparallel marginal hermetically sealed edge zones and at least one openedge zone, the cellular material disposed within said marginalhermetically sealed edge zones and said open edge zone being crushed tocollapse the cells in said cellular material and said hermeticallysealed edge zones being folded and sealed to the adjoining surfaces ofthe contaIner whereby said hermetically sealed edge zones impart arelatively high degree of stiffness to said container and therebyenhance the protective qualities thereof.